An infrared thermometer is equipped with a probe protruding outwardly from part of a case body. The distal end of the probe is open and is provided internally with a radiant-energy temperature sensor (a thermophile, for example). When the tip of the probe is inserted slightly into the ear canal, heat rays (infrared rays) emitted from the external ear impinge upon the radiant-energy temperature sensor. The temperature sensor is connected to a temperature measurement circuit provided in the case body. The measurement circuit determines body temperature based upon the output of the temperature sensor. Thus, the infrared thermometer is capable of measuring body temperature in a short period of time basically without making contact (at least the temperature sensor does not contact the human body).
In order to prevent the transmission of various diseases, a sanitary cover is fitted over the tip of the probe of the infrared thermometer at the time of temperature measurement. The sanitary cover is replaced for each individual (patient) subjected to measurement and is discarded after use.
Typical examples of such a cover fitted over the probe of a speculum which includes an infrared thermometer are described in U.S. Pat. No. 4,662,360 and EP-A-419,100.
A sanitary cover described in the former comprises a tubular body and a membrane, which is transparent to infrared radiation, covering an opening at the tip of the tubular body. The tubular body is fabricated by injection molding and the membrane is attached thereto by thermal welding.
The probe cover described in the latter comprises a sheath fitted on a probe and having a closed distal end face serving as a window, and a ring attached to a base end of the sheath by ultrasonic welding and engaged with the probe. The sheath is produced using a forming punch.
Since both covers comprise two individually fabricated parts that are combined, the separate parts are costly and considerable labor is involved in manufacture. An additional problem is low productivity since batch treatment is unavoidable, thus making it impossible to work the covers continuously.
The simplest structure is one in which two small holes are formed in the end or edge of a rectangular or circular film (sheet). The film is used to cover the tip of the probe and is secured by engaging the holes with projection provideds on the base end of the probe.
Since this probe cover is such that the holes are merely formed in the film, problems arise in that it is difficult to attach the cover to the probe. Moreover, the film tends to shift from the attached position. If the film shifts or becomes detached, its infection preventing function is lost.